Production of sterols



Patented Dec. 26, 1933 i 1,097

UNITED STATES PATENT orncs 1,941,091 monuo'rron or STEROLS Robert F. Light, Mount Vernon, and Charles N. Frey, New York, N. Y., assignors to Standard Brands Incorporated, Dover, DeL, a corporation of Delaware No Drawing. Application March a, 1930 Serial No. 432,980

4 Claims. (01. 260-156) This invention relates to processes of extractmethod of carrying out the process is as follows: ing sterols fromyeast and other plant and animal To 2 kilograms of compressed yeast, about 2 products and more particularly to processes of liters of water containing about of sodium extracting sterols, particularly ergosterol, from hydroxide is added. The mixture is then cooked 5 yeast, and especially from compressed yeast. under lbs. pressure while stirring for about A general object of the invention is to provide 5 hours to obtain a good liberation of the ergoa process of extracting and recovering such substerol and substantially a destruction of the eelstances in a convenient, efiicient and economical lular material, thereupon the solution is allowed manner, in a relatively pure form, and with the to cool. About liter of benzol is then added 10 attainment of high. yields. and the mixture is refluxed with constant stir- A more particular object of the invention is to ring for about 10 minutes, during which time the provide a process by which such substances can benzol takes up the liberated ergosterol. Then, be separated and recovered by a novel use of a the benzol is allowed to separate out in a layer water solution of a saponifying agent in combinaand is drawn off; the benzol is removed by evap- 15 tion with a solvent for the substances which is oration and the oily residue is purified by taking immiscible with the said water solution. up in alcohol, filtering, crystallizingout the ergo- Other objects of the invention will in part be sterol, washing with hot water to remove the obvious and will in part appear hereinafter. soap and recrystallizing from alcohol until a The invention accordingly comprises the sevproduct of the desired purity is obtained.

20 eral steps and the relation and order of one or Generally speaking, the caustic alkali may be more of such steps with respect to each of the used in concentrations ofv from 6% to 15% in others thereof, which will be exemplified in the solution, potassium hydroxide may be substitutprocess hereinafter disclosed, and the scope of ed for the sodium compound and the alkali carthe application of which will be indicated in the bonates may be likewise used in concentrations 25 claims. of from 8% to 20%. Moreover, the pressure used so The sterols comprise a group of fatty submay range from 20 to 30 lbs. and other substances stances which are characterized by the fact that relatively immiscible with water such as toluol, they are unsaponifiable, and previous methods of ethylene dichloride, petroleum ether or chloroextracting these substances have utilized first form may be used instead of benzol, if desired,

30 either a direct extraction with ether or some in amounts of from to liters. By such proother suitable solvent, followed by saponificacedure, yields of approximately 1 gram of ergotion or a saponifying step and then one or more sterol have been obtained per kilogram of yeast. separate extraction steps, whereby unsaponifi- It will thus be seen that there has been proable constituents are separated from the saponvided a process which can be conveniently and 35 ified mass. expeditiously carried out to give a high yield of In accordance with the principles of the presproduct, and since certain changes may be made ent invention, the sterol containing material, in carrying out the above process without departsuch as, for example, compressed yeast. is cooked ing from the scope of the invention, it is intended under pressure with an aqueous solution of a that all matter contained in the above description 40 compound having an alkaline reaction such as shall be interpreted as illustrative and not in for example a hydroxide or carbonate soluble in a limiting sense. v water, until the hydrolysis of the saponifiable It is also to be understood that the following constituents is sufiiciently effected and the unclaims are intended to cover all of the generic ap fi Constituents comprising the st l and specific features of the invention herein de- 45 and Particularly e gosterol are released. The scribed, and all statements of the scope of the inmixture is then cooled and a small amount of a vention which, as a matter of language, might solvent for sterols which is immiscible with the be said to fall therebetween. solution is added, whereupon the mixture is re- Having described our invention, what we claim fluxed with stirring until the sterols have gone as new and desire to secure by Letters Patent, is:

50 into solution in the said solvent, and the solvent 1. A process of obtaining sterols from crude subcontaining the sterols in solution is removed and ta ces containing the same which comprises the sterols are purified in any'suitable manner. saponifying the substances by cooking under Altho the materials, pressures, and times about 20 lbs. pressure with a water solution of an of trea ay be varied, as will be read y alkaline material until the sterols are liberated,

55 understood by one skilled in the art, a preferred cooling th mixture, adding a solvent for sterols yeast by cooking under about 20 lbs. pressure with sterols are liberated, cooling the mixture, adding benzol, simultaneously refluxing and stirring until the sterols are dissolved therein, separating the solvent from the aqueous alkaline solution, and evaporating the solvent to obtain the sterols as a residue.

3. A process of obtaining sterols from compressed yeast which comprises saponiiying the yeast by cooking under about 20 lbs. pressure with a water solution of caustic alkali until the sterols are liberated, cooling the mixture, adding benzol, simultaneously refluxing and stirring until the sterols are dissolved therein, then separating the solvent from the aqueous i1 met 1 i solution while hot, and evaporating the solvent toobtain the sterols as a residue; for each 2 kilograms of yeast the materials used being substantially in the following proportions: water 2 liters, caustic alkali from to 300 grams, benzol about liter.

4. A process of obtaining sterols from crude substances containing the same which comprises saponifying the substances by cooking under pressure in the presence of water and analkaline material until the sterols are liberated, cooling the mixture, adding a solvent for sterols which is sufflciently immiscible with water to layer 011 readily, simultaneously heating and stirring until the sterols are dissolved therein, then separating the solvent from the alkaline solution while hot, evaporating the solvent to obtain the sterols as a residue, taking up the residue in alcohol, fi1ter= ing, crystallizing out ergosterol, washing the crystals with hot water to remove the soap, recrystallizing from alcohol to obtain a pure product.

honm'r n'. LIGHT. i s N. 

